During routine daytime use, public transit vehicles, such as railroad passenger cars, are illuminated by means of daylight, and possibly some minor ambient artificial lighting. During nighttime use, general low level ambient lighting is used to guide passengers along a proper unobstructed routes to the exits; however, it has been found that such general low level lighting is potentially inadequate during emergency situations, which is when a lighting systems, especially one that guides passengers to exits, may be needed the most. Such emergency situations might include a railway passenger car being on fire and filling with smoke, or being driven off a bridge or trestle and thereby being at least partially submerged in water. Each of these types of emergency situations has been known to occur and has led to loss of life.
During a fire in a railway passenger car, the car tends to fill with smoke, except possibly for the bottom one or two feet of the car. It is therefore very difficult, if not impossible, for a passenger to see the closest exit. Typically, since the passenger may be panicking due to the flames, heat, and smoke, it is difficult to quickly determine which direction to head to the nearest exit. Exit signs, which are typically located near the ceiling at exit doors, cannot be seen. Often, passengers will spot a light and crawl on their hands and knees to that light, believing that the light is an exit; however, the light often turns out to be the fire itself. It is also quite easy in this type of situation for passengers to become somewhat trapped under the seats of the railway car, and even become injured or stuck. Further, corridors of railway passenger cars are typically quite narrow, which can lead to extreme congestion and confusion in an emergency situation.
It is also very common during such emergency situations, such as fire or immersion in water, for any lighting system to become inoperable by way of general damage, burning or melting of components, short circuiting, and so on. Further, typical lighting systems do not specifically lead and point to exits.
What is needed is an emergency low level lighting system that is on constantly and that is affected as minimally as reasonably possible by water, fire, smoke, physical abuse, and so on. Further, such emergency low level lighting systems should lead or point to exits, so that passengers may follow the lighting system to an exit during emergency conditions.